Plural-purpose controller for electric sewing machines and the like



Aug. 5,1958

Filed Sept. 50} 1955 K. WINZ PLUR AL-PURPOSE CONTROLLER FOR ELECTRICSEWING MACHINES {\ND THE LIKE 2 Sheets-Sheet 1 AfTOAA/EY Aug. 5, 1958 K.wmz 2,846,552

PLURAL-PURPOSE CONTROLLER FOR ELECTRIC SEWING MACHINES AND THE LIKEFiled Sept. 50, 1955 2 Sheets-Sheet 2 IN V EN TOR. A42? M/vz UnitedStates Patent PLURAL-PURPOSE CONTROLLER FOR ELECTRIC SEWING MACHINES ANDTHE LIKE Karl Winz, Kaiserslautern, Germany, assignor to G. M.

Pfalf A. G., Kaiserslantern, Pfalz, Germany, a corporation of GermanyApplication September 30, 1955, Serial No. 537,860

Claims priority, application Germany October 9, 1954 5 Claims. (Cl.201--48) The present invention relates to improvements in plural-purposestarters or controllers for electric sewing machines and the likeembodying a variable resistance unit and actuating means therefor forcontinuously varying the motor or operating speed.

It has been customary in the past, especially in the case of electricsewing machines, to construct the controller for either foot, knee orpull control for variation of the motor speed. This has made itnecessary to provide and keep in stock a considerable number of units ortypes of controllers and/ or machines to suit individual customer desireor requirements. This constitutes an undue burden on both thefabrication and sales and marketing operations, not to speak of theadded manufacturing and overhead expense involved.

While it has already been proposed to construct a controller unit sothat it can be adapted for use in different modes of operation, inparticular for either foot or knee control, the prior constructions havenot been fully satisfactory both with regard to a quick and instantchange from one to the other mode of operation by the average personwithout the use of special tools or skill, as well as by the lack ofsimple means for converting and adapting the units instantly andefiiciently from any one to another of the conventional operating modes,that is, foot, knee or pull control, to suit any existing operatingcondition or requirements.

Accordingly an important object of the present invention is theprovision of a plural-purpose starter or controller for electric sewingmachines or the like which is both simple in design and construction andwhich will enable a quick and ready conversion or adaptation from anyone to another of the conventional operating modes, that is, by a footpedal, knee lever or pull control element respectively.

Another object of the invention is the provision of a basicplural-purpose controller unit which will require a minimum ofattachment or conversion parts for adapting the unit to any of thevarious operating modes or controls.

A further object of the invention is the provision of a readilyadaptable plural-purpose controller which can be converted from one toanother operating mode with a minimum of operations and without the useof special tools or skilled labor.

Still a further object is the provision of adjustable mounting means fora plural-purpose controller of the type referred to, to ensure adequatestability and other conditions of operating safety in the various usesand operating modes of the unit.

The above and further objects, as well as novel aspects of the inventionwill be better understood from the following detailed description of apractical embodiment taken in reference to the accompanying drawings,forming part of this specification and in which:

Fig. 1 is a perspective bottom view of the basic construction unit of aplural-purpose controller embodying 2,346,552 Patented Aug. 5, 1558 theprinciples of the invention, the bottom wall of the unit being removedto reveal the inside construction;

Fig. 2 is a partial view of Fig. 1 with the bent lever removed and itspivot shaft shown separately in exploded view;

Fig. 3 is a partial perspective view of the angular control lever foreifecting foot-controlled operation of the controller;

Fig. 4 is a schematic side View of the assembled controller shown on areduced scale and adapted for foot operation;

Fig. 5 is a perspective view showing the controller adapted for kneelever control and mounted in vertical position on the inside of thesewing machine cabinet or the like;

Figs. 5A and 5B are separate plan views, respectively, of the bentactuating lever and extension member therefor for knee lever control;

Fig. 6 is a perspective top view of the basic controller unit with thebent actuating lever removed to reveal the auxiliary control shaft usedfor pull control;

Fig. 6A shows the auxiliary actuating lever and fastening screwtherefor, provided for pull control of the unit;

Fig. 7 is a further perspective view of the basic controller unitaccording to the invention shown mounted upon the cabinet wall of asewing machine or the like for pull-controlled operation; and

Fig. 8 is a perspective bottom view of the controller unit showing animproved feature for supporting and mounting the units for use in itsvarious operating modes.

Like reference numerals identify like parts throughout the differentviews of the drawings.

Referring more particularly to Figs. 1 to 3, the reference numeral 1eindicates an oblong flat housing of any suitable material (metal,plastic, etc.) preferably provided with a slanting top, Fig. 4, andbeing fitted at one of its short ends with a current supply base orsocket 11 for connecting the controller to an electric power line ornetwork. Mounted within the casing 10 is a variable electricalresistance unit 12, preferably, though not limitatively, of the typecomprising a stack or pile of compressible carbon elements, such asdiscs or plates, to provide a stepless or continuously variableresistance proportional to a compressive control force applied to thestack. The resistance 12 serves in a known manner to vary the operatingcurrent or voltage of the driving motor of a sewing machine or the like,to correspondingly vary the motor speed. In case of a sewing or similarmachine, with the load subject to substantial fluctuations, the motor isadvantageously of the series wound type with the controller resistanceconnected in series with the motor winding, to enable an effective speedcontrol under varying load conditions, in a manner well known to thoseskilled in the art.

The special construction of the resistance unit 12 provided withsuitable terminal means 13 is immaterial for the present invention, thelatter relating to improved operating mechanism or instrumentalities toenable a plural control and operation. There is provided for thispurpose an actuating rod 15 extending through or otherwise guided by theinsulating casing of the unit 12, a coil spring or the like beinginterposed between one of the projecting ends of said rod and thecompressible resistance (see also Fig. 4), whereby a pull exerted uponthe opposite end of the rod 15 results in a varying stack pressure uponthe carbon elements and, in turn, a corresponding variation of theelectrical resistance of the unit.

In order to operate the controller in the various modes or mannerspointed out, there is provided according to the invention anintermediate actuating member 14 of a suitable insulating material andsecured to the projecting end of the rod on the side opposite to thecontrol or balance spring 16. Connecting member 14 may be operated alonga predetermined substantially linear path by either one of two controlmeans in order to adapt the controller for foo-t control, knee control,or pull operation, to suit existing conditions or requirements. Morespecifically, for effecting foot or knee operation of the controller,there is provided a bent actuating lever 17, Fig. 3, having a shortlever arm in the form of two parallel elements or prongs 18 and arelatively longer lever arm serving as a foot pedal 28, Fig. 4. Lever 17is removably supported by a transverse pivot shaft 19 secured to thehousing 10 in any suitable manner, such as by means of a pair ofdepending perforated ears or supports 21 formed by inwardly bendingportions of the housing top wall, the shaft 19 being passed through ahole or here 22 in one of the side Walls of the housing and having athreaded end 23 engaging the internally threaded bore of one of thesupports 21 to firmly and removably secure the shaft in place.Alternatively, shaft 19 may be secured to or supported in suitable boresof the opposite side walls of the housing, to dispense with the separatesupports 21.

The bent actuating lever 17 is pivoted upon the shaft 19, the latterpassing through holes 24 in the lever arms 18, operative connection ofthe latter with the member 14 being effected by the cut-out ends 25 ofthe arms 18 engaging the projecting ends of a rod or shaft 26 secured inthe member 14. The arms 18 of the bent lever are passed through anopening 27 in the top wall of the housing 10 such that the pedal or arm20 of the lever extends above and along the housing 10, as more clearlyshown in Figs. 4 and 5 of the drawings. The end of the arm 2t carries aremovable roller 28 to provide a pedal for easy and convenient footoperation of the controller. With this construction and operation thefoot of the operator produces a further mechanical advantage by actingas a cantilever with the heel 30 providing a fixed pivot point and thesole 31 engaging the roller 28 and acting as a lever arm, in the mannershown in Fig. 4. The construction of the lever or foot pedal andoperating has the result of a reduced stroke or minimum deflecting anglerequired to cover the full range of the resistance variation or speedcontrol, resulting, in turn, in greater convenience of operation andreduced fatigue on the part of the operator over prolonged operatingperiods.

If the controller is to be used for knee lever operation, the roller 28of the arm or actuating member 20 is removed, such as by unscrewing theshaft 32 of the roller, Figs. 5 and 5A, removing the roller andreplacing it by an extension member or knee lever 33, Figs. 5 and 5B,removably held by the arm 20 in any suitable manner, such as by means ofan extending angularly or reversely bent tongue 34 engaging the end ofarm 20. In this case the controller in advantageously mounted in avertical position on the inside of the cabinet of a sewing machine orthe like, as shown in Pig. 5.

There are further provided according to the invention exchangeable meansor instrumentalities for adapting the unit to pull control or operation.For this purpose a further auxiliary lever arm 35 has one end pivotallyconnected to the intermediate member 14 and has its opposite end securedto a shaft 36 being at right angle to the shaft 19, in the exampleillustrated, and journaled in the bottom and top walls of the housing,shaft 36 extending slightly above the housing top and being concealed bythe member 28 in the foot or knee operated position of the unit. Theextendnig end of shaft 36 has a square shape, as shown at 37, Fig. 6,for removably connecting to it a further auxiliary operating lever 38parallel to and overlying the top wall of the housing, as shown in Figs.6A and 7. For this purpose, lever 38 has a square opening at one endfitting the end 37 of shaft 36 and being secured in place by a screw 40or in any other Suitable manner. As a result, the assembly comprisingthe arm 35, shaft 36 and arm 38 provides an additional actuating meansof the resistance 12 controlled by applying a downward pull to the freeend of the lever arm. The latter may be provided with a furtherfastening screw 41 or the like for attaching a suitable pulling member,such as a cord or rod 42, as shown in the drawing.

According to a further feature of the invention, a plural-purposecontroller of the type described is fitted with means to insure bothhigh mechanical stability and other safety conditions in the variousoperating modes or positions of the unit. For the latter purpose, thecontroller housing 10 is fitted, as shown in Fig. 8, with supports orfeet 45 of rubber or an equivalent material and adjustably secured tothe base or bottom wall of the housing, in such a manner as to belocated either within the confines of the housing to serve as supportsproviding adequate mechanical stability of the unit in the footoperatedposition, Fig. 4, or to extend beyond the edges of the housing to serveas means for mounting the controller upon a cabinet wall or the like,for pull or knee control, as shown in Fig. 5. In the latter case, thefeet 45, if made of rubber or an equivalent material, act as heatinsulators or separators, preventing excessive heating of and damage tothe cabinet, especially a Wooden cabinet, whreby to dispense with theneed of any separa-e heat insulation.

For this purpose, four perforated feet 45, as shown in Fig. 8, havingmounted therein suitable eyelets or hollow rivets 46, are each securedto one end of the slotted adjusting plates or slides 47 which aresecured to the underside or bottom wall 48 of the housing 10 by setscrews 50 passing through the slots 51 of the slides 49 and engagingcorresponding tapped holes in the wall 48. As a result, the feet 45 maybe adjusted in any desired position by loosening and re-tightening thescrews 50. Thus, for foot operation of the controller, the feet may belocated within the confines of the housing 10, as shown for the upperleft hand foot and the lower right hand foot in the drawing. This willinsure optimum mechanical stability of the controller for use in thismode of operation, as shown in Fig. 4. For mounting the controller in avertical or other position upon a cabinet wall or the like, for kneelever or pull control, the feet 45 are extended beyond the bottom wallof the housing 10, as shown for the lower left hand foot and the upperright hand foot in Fig. 8. As is understood, the adjusting angle of thefeet or slides 47 may be either normal to the edges of the housing, asindicated by the arrows in the drawing, or at any other angle byrotating the slides to a desired position prior to the tightening of thescrews 50, to suit existing conditions and mounting requirements.Mounting of the controller may then be simply effected by means ofscrews or bolts passing through the holes in the rivets or eyelets 46.Thus, Fig. 5 shows the unit mounted upon the vertical inside wall of asewing machine cabinet with the feet 45 extended at right angle to thehousing and acting both as resilient supports and heat insulators, inthe manner pointed out and readily understood from the foregoing.

In the foregoing the invention has been described with reference to aspecific illustrative device. It will be evident. however. that changesand modifications. as well as the substitution of equivalent parts andelements for those shown, may be made without departing from the broaderscope and spirit of the invention as set forth in the appended claims.The specification and drawings are accordingly to be regarded in anillustrative rather than in a limiting sense.

I claim:

1. In a controller for electric sewing and the like machines comprisinga fiat casing having top and bottom walls, electrical resistance meanswithin said casing, an intermediate control member connected to saidresistance means being normally resiliently urged to a position ofmaximum resistance and operable over a predetermined path in a directionsubstantially parallel to said casing walls, to vary the resistancebetween maximum and minimum, and vice versa, for controlling theoperating speed of said machine, a first angular control lever having afirst lever arm extending substantially transversely to said casingwalls and having one end engaging said member, means removably andpivotally mounting said lever arm upon said casing with the opposite endthereof protruding beyond the top Wall of said casing, a second leverarm of said control lever forming an angle with said first lever arm andextending alongside and in spaced relation to said top wall, whereby toallow control of said member by foot pressure applied to the free end ofsaid second lever arm in the horizontal op erating position of thecontroller, and a second control lever having a first lever arm movablein a plane substantially parallel to said casing walls, said last leverarm secured to said member and pivotally mounted upon said casing, asecond lever arm removably connectible to said first lever arm of saidsecond control lever, for controlling said member independently of saidfirst control lever, thereby to allow of control of said resistancemeans with said casing arranged in vertical mounting position by avertical pulling force applied to said second lever arm of said secondcontrol lever.

2. A controller as claimed in claim 1, including a removable rollermounted upon the free end of said second lever arm of said first controllever, and an auxiliary knee-operated lever arm removably connectible tosaid free end upon removal of said roller, for effecting knee-operatedcontrol of said resistance means in the vertical mounting position ofthe controller.

3. A controller as claimed in claim 1, wherein said second lever arm ofsaid second control lever is removably connectible and extends beyondand in the direction of the top Wall of said casing.

4. A controller as claimed in claim 1, including a plurality ofsupporting feet upon the bottom wall of said casing, and means foradjusting said feet to extend beyond the confine of said casing, therebyto serve, respectively, as supporting means in the horizontal operatingposition and as mounting means in the vertical operating position of thecontroller.

5. A controller as claimed in claim 1, including a plurality ofperforate supporting feet upon the bottom wall of said casing consistingof resilient and heat resistant material and fitted with metal eyelets,and means for adjusting said feet to extend beyond the confine of saidcasing, to serve, respectively, as supporting means in the horizontaloperating position and as mounting means in the vertical operatingposition of the controller.

References Cited in the file of this patent UNITED STATES PATENTS1,772,361 Mross Aug. 5, 1930 2,181,543 Bentz Nov. 28, 1939 2,193,964Hastings Mar. 19, 1940 2,557,259 Chason June 19, 1951 2,561,556 BellJuly 24, 1951 FOREIGN PATENTS 594,933 Germany Mar. 15, 1934 1,016,591France Aug. 27, 1952

